IC cards, which are of about the same width and length as a typical credit card, have connectors at their front ends for engaging a connector in a card-receiving slot of an electronic device such as a notebook computer. As defined by PCMCIA (Personal Computer Memory Card International Association) the cards have a width and length of 54 mm and 85.6 mm respectively, with three different types having thicknesses of 3.3 mm, 5 mm and 10.6 mm. Some more recent cards allow connection of the card to a local area network (LAN) by providing a receptacle connector at the rear of the IC card. An adapter cable assembly has a plug connector at its front end that plugs into the receptacle connector at the rear of the card. U.S. Pat. Nos. 5,387,110 and 5,411,402 describe plug connectors of this type.
Although prior plug connectors of the above type commonly provided 22 contacts, newer IC card designs require a larger number of contacts. One type of connector having the physical format of the PCMCIA card type II (height or thickness of 5.0 mm) has a pluggable front end of a width of 28.80 mm and requires a minimum of 36 contacts. The design must include provisions for keying (to assure insertion in the proper orientation) and a latching mechanism with locking capability. One type of prior art latching mechanism described in each of the above two patents, includes a pair of arms projecting forwardly from the plug connector and insertable into an aperture of the receptacle connector. Each arm has a lateral projection that prevents unmating of the connectors until flat handles on the top and bottom of the plug connector are moved rearwardly to allow the arm to deflect toward each.
A major disadvantage of the above-described latch mechanism is that it occupies considerable space that could otherwise be occupied by contacts. For example, U.S. Pat. No. 5,387,110 provides a lateral width for the latching mechanism, that otherwise could accommodate a lateral row of six contacts. If upper and lower rows of contacts are provided, then such a latch would occupy space that otherwise could accommodate twelve contacts. It would be desirable if a latching mechanism were provided that occupied less lateral space.
In some applications, an electronic device may have two or more card-receiving slots stacked one above the other, and two or more plug connectors can mate with the rear ends of the stacked cards. In that case, it is difficult to gain access to flat handles at the top and bottom of a connector to unlatch it so that the connector can be pulled out. A latching system which enabled operation even though it was part of a plug connector lying in a stack, would be of value.